[SOLVED] Some holes disappear in 2-body fusion

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ulidtko
Posts: 8
Joined: Tue Oct 27, 2020 10:19 pm

[SOLVED] Some holes disappear in 2-body fusion

Postby ulidtko » Wed Oct 28, 2020 12:16 am

Greetings! New user here.

I'm a long-time Open Source enthusiast, and just recently started learning FreeCAD. Fascinating project I must say! Having modeled a few solid things in the past using the wrong tool for that (cough-cough Blender :roll:) I'm shocked how accessible, easy to approach and powerful FCD is. TechDraw workbench deserves special mention (the Drawing workbench should be just removed, I was disappointed and confused by it for quite a while).

You guys, the core team, everyone who contributes, reviews PRs, fixes CI, maintains the wiki, helps on the forums & IRC, etc — are carrying gravely important mission, that's not to be understated.

I do really mean that; but let me move on to something interesting (I hope).

This model I made has two bodies: body base and pulley teeth. The former has holes in it. Hmmm I shouldn't spend words on it, here's how it looks:
Screenshot from 2020-10-27 01-17-22.png
Screenshot from 2020-10-27 01-17-22.png (242.05 KiB) Viewed 232 times
The problem is, for a final tech drawing I need these merged/fused (and refined)
... but whichever approach I try, the small holes on the bottom near the teeth disappear:
Screenshot from 2020-10-27 01-26-05.png
Screenshot from 2020-10-27 01-26-05.png (174.43 KiB) Viewed 232 times
I tried all of:
  • Part Union
  • OpenSCAD Union
  • PartDesign Boolean
... all give the same result: the bottom holes disappear.

I was careful to not place the holes touching any edge or wall, there's spacing. The diameters of teeth & base body are explicitly set at 90.5; adding spacing between them does not help:
photo_2020-10-27_01-48-51.jpg
photo_2020-10-27_01-48-51.jpg (34.24 KiB) Viewed 232 times
The model was made in v0.18 (r16158) and maybe there's something funny in the document history — as I was fumbling around a lot and had to make several reattachments, recomputes and error fixes.

I tried loading it in v0.19 (r22846-Linux-Conda_glibc2.12-x86_64.AppImage) but that didn't help anything; the holes still disappear with any of the fusion methods.

The FCstd file somehow doesn't fit the forum upload limit; check here https://drive.google.com/file/d/1gdzxJb ... sp=sharing

Can anybody else confirm the behavior? If so, I should probably report this at the Mantis bug tracker.

More importantly for me... are there workarounds I don't see? Perhaps it's possible to erase a circle in TechDraw? I don't really need the parts fused, if not for trying to obtain neat tidy drawing.
Last edited by ulidtko on Wed Oct 28, 2020 1:28 am, edited 1 time in total.
chrisb
Posts: 30699
Joined: Tue Mar 17, 2015 9:14 am

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby chrisb » Wed Oct 28, 2020 12:51 am

Moved to help forum.

I have some difficulties to download, but I would guess it's a coplanar issue.
You need at least FreeCAD 0.19.23300 to edit my current sketches.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
jmaustpc
Posts: 10525
Joined: Tue Jul 26, 2011 6:28 am
Location: Australia

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby jmaustpc » Wed Oct 28, 2020 12:55 am

ulidtko wrote:
Wed Oct 28, 2020 12:16 am
(the Drawing workbench should be just removed, I was disappointed and confused by it for quite a while).
No it should not, it is deprecated but not removed because if it was removed then that would remove compatibility with old FreeCAD files that may contain a "Drawing" object.
chrisb
Posts: 30699
Joined: Tue Mar 17, 2015 9:14 am

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby chrisb » Wed Oct 28, 2020 12:57 am

It was something different: You have changed the tip, so the body didn't reveal it's final state to the outside world. Set it in body base to the final fillet and all is well.
You need at least FreeCAD 0.19.23300 to edit my current sketches.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
ulidtko
Posts: 8
Joined: Tue Oct 27, 2020 10:19 pm

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby ulidtko » Wed Oct 28, 2020 1:12 am

chrisb wrote:
Wed Oct 28, 2020 12:57 am
It was something different: You have changed the tip, so the body didn't reveal it's final state to the outside world. Set it in body base to the final fillet and all is well.
Uhhh... no?
Screenshot from 2020-10-28 03-10-42.png
Screenshot from 2020-10-28 03-10-42.png (114.43 KiB) Viewed 215 times
ulidtko
Posts: 8
Joined: Tue Oct 27, 2020 10:19 pm

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby ulidtko » Wed Oct 28, 2020 1:13 am

jmaustpc wrote:
Wed Oct 28, 2020 12:55 am
No it should not, it is deprecated but not removed because if it was removed then that would remove compatibility with old FreeCAD files that may contain a "Drawing" object.
Okay, sure, I meant "remove with deprecation" :D
ulidtko
Posts: 8
Joined: Tue Oct 27, 2020 10:19 pm

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby ulidtko » Wed Oct 28, 2020 1:17 am

ulidtko wrote:
Wed Oct 28, 2020 1:12 am
Uhhh... no?

Screenshot from 2020-10-28 03-10-42.png
Well, here I forgot to turn off teeth visibility, so there's a line.

This is without the line. Body tip at the last fillet; no holes.
Screenshot from 2020-10-28 03-16-51.png
Screenshot from 2020-10-28 03-16-51.png (138.9 KiB) Viewed 208 times
chrisb
Posts: 30699
Joined: Tue Mar 17, 2015 9:14 am

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby chrisb » Wed Oct 28, 2020 1:21 am

Tip is not at Fillet001, it is - as far as I can see from the image - still at "bearing retainer thread".
See https://wiki.freecadweb.org/PartDesign_Body#Tip
You need at least FreeCAD 0.19.23300 to edit my current sketches.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Bance
Posts: 1204
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby Bance » Wed Oct 28, 2020 1:23 am

chrisb wrote:
Wed Oct 28, 2020 1:21 am
still at "bearing retainer thread".
+1 :lol:
ulidtko
Posts: 8
Joined: Tue Oct 27, 2020 10:19 pm

Re: OpenCascade bug? Some holes disappear in 2-body fusion

Postby ulidtko » Wed Oct 28, 2020 1:25 am

chrisb wrote:
Wed Oct 28, 2020 1:21 am
Tip is not at Fillet001, it is - as far as I can see from the image - still at "bearing retainer thread".
OMG that little mark? Sorry, I didn't see it... Missed it completely. How to reset?